Fatal and extensive multiorgan hemorrhages in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis: An autopsy case report.

Introduction: Anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab) is an autoantigen associated with dermatomyositis (DM). Anti-MDA5 Ab-positive DM patients frequently exhibit clinically amyopathic dermatomyositis (CADM), and develop rapidly progressive interstitial lung disease (RPILD). Even with early detection and potent combination immunosuppressive therapy, anti-MDA5 Ab-positive DM patients have a poor prognosis. In the present case report, we present a rare autopsy case of a patient with anti-MDA5 Ab(+) DM with RPILD who exhibited diffuse alveolar damage (DAD) patterning in lung specimens, and extensive hemorrhages in multiple organs. Patient concerns: An 82-year-old Japanese man admitted with bacterial pneumonia was subsequently diagnosed with anti-MDA5 Ab-positive DM based on skin manifestations (mechanic's hand, ulcerated palmar papules, and flagellate erythema), myositis, interstitial pneumonia, and elevation of anti-MDA5 Ab titer. Diagnosis: The patient was diagnosed with anti-MDA5 Ab(+) DM, complicated with RPILD. Interventions: The patient received potent immunosuppressive therapy consisting of pulse methylpredonisolone at a dose of 1000 mg for 3 days, followed by prednisolone at 60 mg/d, a 1000 mg pulse of intravenous cyclophosphamide (IVCY), and oral tacrolimus at 6 mg/d. Intravenous immunoglobulin (IVIG) at a dose of 400 mg/kg/d for 5 days was subsequently administered. Outcomes: Despite triple immunosuppressive therapy and IVIG, the patients' respiratory status deteriorated, and the patient died of respiratory failure on the twelfth day after admission. An autopsy revealed pulmonary DAD and multiorgan hemorrhages, including the left iliopsoas muscle, gastric and bowl mucosa, spleen, and left adrenal gland. Lessons: Multiorgan hemorrhages may be a fatal complication in anti-MDA5 Ab(+) DM patients.